Summit County 2019 Vector Borne Surveillance Report, Weeks 21 and 22 Page 1 Vector Borne Disease 2019 Surveillance Report Summit County Public Health Report Weeks 21 and 22 (October 13 to October 26, 2019) MMWR Weeks 42 and 43 This report will be issued from June through October of each year (or later if West Nile Virus disease is still a concern). Surveillance will include human and veterinary cases and testing of mosquito pools in Summit County. It will also include updates from Ohio and around the nation for all reportable diseases that are transmitted insect vectors. SUMMIT COUNTY SURVEILLANCE Table 1: West Nile virus (WNV) tests ordered in Summit County hospitals Week(s) # of WNV tests ordered this period # of positive WNV tests this period Cumulative # of tests ordered this season Cumulative # of positive tests this season Percentage of positive tests Weeks 1 & 2: 5/26 to 6/8 2 1 2 1 50.0% Weeks 3 & 4: 6/9 to 6/22 5 0 7 1 14.3% Weeks 5 & 6: 6/23 to 7/6 4 0 11 1 9.1% Weeks 7 & 8: 7/7 to 7/20 6 1 17 2 11.8% Weeks 9 & 10: 7/21 to 8/3 9 1 26 3 11.5% Weeks 11 & 12: 8/4 to 8/17 10 0 36 3 8.3% Weeks 13 & 14: 8/18 to 8/30 14 1 50 4 8.0% Weeks 15 & 16: 9/1 to 9/14 12 1 62 5 8.1% Weeks 17 & 18: 9/15 to 9/28 14 0 76 5 6.6% Weeks 19 & 20: 9/29 to 10/12 11 0 87 5 5.8% Weeks 21 & 22: 10/13 to 10/26 5 0 92 5 5.4% Note: Reporting may not be completed each week. Numbers will be updated when reports are received West Nile virus testing (Table 1): During surveillance period Weeks 21 and 22, there were 5 tests for West Nile virus (stand alone or part of an arbovirus panel) ordered by Summit County hospitals, none were positive. So far this season, there have been 5 positive results, all of which were likely to be indication of immunity due to a past exposure and were not active infections (Table 1). Lyme disease testing (Table 2): There were 46 diagnostic test series performed for Lyme disease during Weeks 21 and 22, 5 of which were positive. The CDC currently recommends a two-step process when testing blood for evidence of antibodies against the Lyme disease bacteria (Borrelia burgdorferi). Both steps can be done using the same blood sample. The first step uses a testing procedure called “EIA” (enzyme immunoassay) or rarely, an “IFA” (indirect immunofluorescence assay). If this first step is negative, no further testing of the specimen is recommended. If the first step is positive or indeterminate (sometimes called "equivocal"), then the second step should be performed. The second step uses a test called an immunoblot test, commonly, a “Western blot” test. Results are considered positive only if the EIA/IFA and the immunoblot are both positive.
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Summit County 2019 Vector Borne Surveillance Report, Weeks 21 and 22 Page 1
Vector Borne Disease
2019 Surveillance Report Summit County Public Health
Report Weeks 21 and 22 (October 13 to October 26, 2019)
MMWR Weeks 42 and 43 This report will be issued from June through October of each year (or later if West Nile Virus disease is still a concern). Surveillance will include human and veterinary cases and testing of mosquito pools in Summit County. It will also include updates from Ohio and around the nation for all reportable diseases that are transmitted insect vectors. SUMMIT COUNTY SURVEILLANCE
Table 1: West Nile virus (WNV) tests ordered in Summit County hospitals
Week(s) # of WNV tests ordered this period
# of positive WNV tests this
period
Cumulative # of tests ordered this
season
Cumulative # of positive tests this
season
Percentage of positive tests
Weeks 1 & 2: 5/26 to 6/8 2 1 2 1 50.0%
Weeks 3 & 4: 6/9 to 6/22 5 0 7 1 14.3%
Weeks 5 & 6: 6/23 to 7/6 4 0 11 1 9.1%
Weeks 7 & 8: 7/7 to 7/20 6 1 17 2 11.8%
Weeks 9 & 10: 7/21 to 8/3 9 1 26 3 11.5%
Weeks 11 & 12: 8/4 to 8/17 10 0 36 3 8.3%
Weeks 13 & 14: 8/18 to 8/30 14 1 50 4 8.0%
Weeks 15 & 16: 9/1 to 9/14 12 1 62 5 8.1%
Weeks 17 & 18: 9/15 to 9/28 14 0 76 5 6.6%
Weeks 19 & 20: 9/29 to 10/12 11 0 87 5 5.8%
Weeks 21 & 22: 10/13 to 10/26 5 0 92 5 5.4%
Note: Reporting may not be completed each week. Numbers will be updated when reports are received
West Nile virus testing (Table 1): During surveillance period Weeks 21 and 22, there were 5 tests for West Nile virus (stand alone or part of an arbovirus panel) ordered by Summit County hospitals, none were positive. So far this season, there have been 5 positive results, all of which were likely to be indication of immunity due to a past exposure and were not active infections (Table 1).
Lyme disease testing (Table 2): There were 46 diagnostic test series performed for Lyme disease during Weeks 21 and 22, 5 of which were positive. The CDC currently recommends a two-step process when testing blood for evidence of antibodies against the Lyme disease bacteria (Borrelia burgdorferi). Both steps can be done using the same blood sample. The first step uses a testing procedure called “EIA” (enzyme immunoassay) or rarely, an “IFA” (indirect immunofluorescence assay). If this first step is negative, no further testing of the specimen is recommended. If the first step is positive or indeterminate (sometimes called "equivocal"), then the second step should be performed. The second step uses a test called an immunoblot test, commonly, a “Western blot” test. Results are considered positive only if the EIA/IFA and the immunoblot are both positive.
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Table 2. Lyme disease tests ordered in Summit County hospitals
Note: Reporting may not be completed each week. Numbers will be updated when reports are received Reported Vector-borne diseases in 2019 (Table 3): As of October 26, there were 25 reported cases of Lyme disease; 8 were confirmed by laboratory testing and 17 were suspected cases. Two confirmed cases of malaria, four cases of Rocky Mountain spotted fever, and two cases of ehrlichiosis were also reported.
Table 3: Vector-borne diseases reported for Summit County residents, 2019 cumulative totals (as of October 26, 2019)
Eastern equine encephalitis 0 0 LaCrosse virus disease 0 0 Malaria 2 0 Cases were international travel-related St. Louis encephalitis virus disease 0 0 Zika virus infection 0 0
West Nile virus infection 0 0
Source: Ohio Disease Reporting System (ODRS); only confirmed, probable, and suspected cases are included.
Table 4. Notable mosquito and tick species identifications in Summit County (as of October 31, 2019) Species name Diseases associated # identified Mosquito species
Tick species Ixodes scapularis Lyme disease, babesiosis, anaplasmosis 81
Source: Ohio Department of Health (Identification via mailed specimens, emailed photos and iNaturalist observations)
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Reported aseptic/viral meningitis cases (Table 5): Prior to the reporting season, there were three reported cases of aseptic meningitis, and no cases were reported during Weeks 21 and 22, increasing the season total to 17. Aseptic/viral meningitis is the most common type of meningitis and occurs predominately in the summer and fall. While most aseptic/viral meningitis cases are due to gastrointestinal or respiratory viruses, similar symptoms may be present with arthropod-borne diseases.
Mosquito testing (Table 6): Based on the ODH mosquito testing summary released on October 31, over 91,468 mosquitoes were collected as 2,317 pooled samples throughout Summit County. 36 of the pooled samples tested positive for West Nile virus.
OHIO SURVEILLANCE
Figure 1. Minimum infection rate (MIR) of West Nile Virus in Culex spp. collected in Ohio as of 10/25/2019 West Nile virus infection rates peaked at 4.81 in late August, but remained below average in Ohio (Figure 1). Routine testing of mosquitoes in Ohio officially ended on September 7, but mosquitos suspected of being positive were tested through the end of the season. 263 mosquito pools in Ohio tested positive for West Nile virus, including 36 pools in Summit County. At this time in 2018, Summit County had 646 mosquito pools that tested positive for West Nile virus.
Source: Ohio Department of Health
Table 5. Reported Aseptic/viral Meningitis Cases in Summit County (confirmed & probable), as of October 26, 2019
Week(s) Cases
reported this period
Cumulative cases for
the season
Aseptic meningitis cases reported prior to season (1/1 to 5/25/2019) 3 -
Weeks 1 & 2: 5/26 to 6/8 1 1
Weeks 3 & 4: 6/9 to 6/22 2 3
Weeks 5 & 6: 6/23 to 7/6 2 5
Weeks 7 & 8: 7/7 to 7/20 3 8
Weeks 9 & 10: 7/21 to 8/3 2 10
Weeks 11 & 12: 8/4 to 8/17 3 13
Weeks 13 & 14: 8/18 to 8/30 0 13
Weeks 15 & 16: 9/1 to 9/14 0 13
Weeks 17 & 18: 9/15 to 9/28 2 15
Weeks 19 & 20: 9/29 to 10/12 0 15
Weeks 21 & 22: 10/13 to 10/26 2 17
Source: Ohio Disease Reporting System (ODRS)
Table 6. Mosquito Testing in Summit County (samples processed by noon on 10/31/2019) Mosquitoes identified 91,468
Pooled samples tested 2,317
Positive WNV pooled samples 36
Note: All mosquitoes pools tested were Culex sp.
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Ohio Mosquito-borne diseases (as of 10/31/2019):
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Ohio Tick-borne diseases (as of 10/31/2019):
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Source: Ohio Department of Health Vector Borne Disease Updates
Table 7. Reported Vector Borne disease in Ohio and the United States, 2019
OHIO UNITED STATES
Disease 2019 (as of 10/26)
cumulative Weeks 21 and 22 (10/13 to 10/26)
2019 (as of 10/26) Cumulative
Babesiosis 7 28 1959 Chikungunya 11 0 89 Dengue (includes dengue-like illness) 8 14 825 Eastern equine encephalitis 0 0 36 Erlichiosis / anaplasmosis 30 47 5614 Jamestown Canyon virus disease 0 0 22 LaCrosse virus disease 20 0 36 Lyme Disease 515 Not reported weekly by CDC Malaria 53 16 1305 Powassan virus disease 0 0 26 Spotted fever rickettsiosis 68 14 3555 St. Louis encephalitis virus disease 0 0 11 West Nile virus infection 2 2 805 Zika virus infection, non-congenital 0 1 15 Note: Data is provisional and subject to change
Special note for travelers: Ohioans traveling to areas where local transmission is occurring should be aware of the ongoing situation and make every effort to avoid mosquito and tick bites. Additional information can be found from
the Centers for Disease Control and Prevention (CDC)'s Travelers' Health and Pan-American Health Organization websites.
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Figure 2. West Nile virus activity by state – United States, 2019 (as of October 29, 2019)
WNV infections in mosquitoes, birds, sentinel animals, or veterinary animals have been reported to CDC ArboNET from all 48 contiguous states except: Maine and West Virginia.
West Nile virus infections in humans have been reported to CDC ArboNET from all 48 contiguous states except: Delaware, Maine, New Hampshire, Rhode Island, Vermont, and West Virginia.
Other mosquito-borne disease acquired within continuous US**Other mosquito-borne disease acquired outside continuous US*West Nile virus diseaseSpotted Fever Rickettsiosis, (including Rocky Mountain spotted fever)Ehrlichiosis / anaplasmosisBabesiosisLyme Disease
Notes: * Includes imported cases of malaria, chikungunya, dengue, and Zika virus infection ** Includes LaCrosse virus disease and St. Louis encephalitis virus disease Source: Ohio Disease Reporting System (ODRS)
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Figures 4 and 5. West Nile and Lyme disease cases in Ohio
Source: https://odh.ohio.gov/wps/portal/gov/odh/know-our-programs/zoonotic-disease-program/news-and-events/vectorborne-disease-update About this report: Reporting agencies include Summit County hospital laboratories and the Ohio Department of Health. Vector-borne disease case data for Summit County are obtained from the Ohio Disease Reporting System. Many thanks to all agencies who report vector-borne disease data weekly. Reporting from participants may not be complete each week. Numbers may change as updated reports are received. For questions, please contact Joan Hall ([email protected]) or Tracy Rodriguez ([email protected]), Summit County Public Health Communicable Disease Unit (330-375-2662). This report was issued on November 5, 2019.
